temperature between the cooling body and the air as high as 200° C. and 300° C. In the author's experiment, however, the tube had a vacuum jacket, so that the heat lost by convection was quite negligible. As the difference of temperature was, comparatively speaking, small, we saw by Stefan's law that the author's assumption was justifiable. In the speaker's opinion the real "Newton's law of cooling was of great importance in practical work, and he thought that teachers and the writers of text-books ought to lay greater stress on it. Dr. W. H. ECCLES called attention to the fact that at first sight the method would be thought to be incapable of high accuracy, because of the form of the expression for K, the conductivity. This expression had as its denominator what was practically the difference between two nearly equal magnitudes. and these magnitudes were themselves differences. That was to say, the denominator was of the nature of a second differential coefficient of an experimental curve. That such consistent results were obtained indicated remarkable precision of experiment. Prof. LEES asked how small a difference of temperature throughout the cross-section would have been detected by the thermo-couple. Dr. GRIFFITHS, in reply, stated that, as shown in the earlier paper, the distribution of the flow was not important, so long as the isothermals were plane. The AUTHOR Communicated the following:-In reply to the Chairman, Prof. Lees, it should be stated that a difference of temperature of 0.05° C. over a horizontal surface would easily have been detected in any position of the cathetometer. In the neighbourhood of the "zero isothermal" all resistances, except that of the galvanometer and wires, could be removed and a more delicate test made. It is safe to say that in this neighbourhood a difference of o'02° C. would have been detected easily. Thus the isothermals are remarkably horizontal, the result far exceeding the author's expectations. Mr. F. E. Smith has raised an important point in his remarks about the "cold junction" at the temperature of the enclosure. The cold junction could not be inside the vacuum, as iron and constantan cannot be fused through glass and a vacuum of high standard maintained. An attempt to surround an earlier vacuum vessel with a glass water jacket (it is necessary to be able to see through the vacuum when adjusting the carrier-tube) resulted in its collapse, and no risks were taken with the present vessel, which is valuable, as at least ten attempts at making a third have failed. The "cold junction was maintained in a tube under water just outside the vacuum vessel to protect it from air draughts, but on holding it in the air just outside the vacuum vessel no serious temperature difference was recorded. The vacuum, of course, was of "thermos" or X-ray standard. When the "warm junction" was in such a position as to produce no electric current the zeroisothermal was located. The author cannot doubt that the temperature of the cold junction was rightly that of the enclosure: for it stood the double test of Newton's law holding with respect to it in a statical experiment, as well as the constancy of the ratio log /L in many dynamical experiments. The height of the zero-isothermal varies in every experiment, being higher the faster the flow, as can be seen in the actual temperature curves given in the paper previously alluded to. Under no flow the zero was very low, being near the lower extremity of the vacuum-jacketed portion of the experimental tuba-too low, in fact, to allow of the test 01/02 I over any considerable range. θα -02 A paper entitled "Polarisation and Energy Losses in Dielectrics was read by Dr. A. W. ASHTON, M.I.E.E. The object of the paper is to discuss the relations which should exist between the coefficients in Pellat's equation (as modified by Schweidler), giving the displacement in a viscous dielectric as a function of the time of charge and the P.D. Taking the modified equation— NEWS Di KEO+ KE。Σ(I-e-at) the charging current for constant voltage becomes for to it = KE。Zaee-at, and in the series of exponential terms a and can be so chosen as to make Zaɛe-at-ẞt-n. The author makes the following deductions among others :-Where the polarisation current is proportional to t-n, the viscous capacity of any group of molecules having the same time constant of displacement is proportional to the (1=n)th power of the time constant. For values of n between o'5 and 1.5 the maximum energy loss occurs in those groups for which a does not greatly differ from p, where p=2TS. For all positive values of n less than 2, the alternating current conductivity is proportional to the nth power of the frequency. Experiments by Addenbrooke, Fleming and Dyke, Curtis and H. A. Wilson are quoted in support of the theoretical deductions. The paper includes a brief résumé of Pellat's theory. DISCUSSION. Dr. RUSSELL said that the author's method was ingenious, and that the formula deduced for the dielectric current agreed well with many experimental results. He thought, however, that Pellat's theory was not sound and that von Schweidler's modification of it was too elaborate to be of much practical use. He pointed out that Dr. Grover had proved that, from the mathematical point of view, Hopkinson's and von Schweidler's theories were identical. He considered that Fleming and Dyke's experimental results could not be ignored, and that none of the theories advanced up to the present explained them satisfactorily. Very different formulæ gave results which were practically identical over wide ranges, and so they were of doubtful help in enabling us to discover the causes of the phenomena. He considered that the nomenclature of dielectric theory stood badly in need of standardising. For instance, what the author called the displacement was practically the same as Maxwell's electric displacement, but Sir J. J. Thomson and several other writers called it the polarisation. Dr. ECCLES stated that the paper compelled remark on the artificial nature of Pellat's hypothesis. This hypothesis led to an expression for the displacement current as a sum of exponential terms. Experiment required it to be a power of t, or the sum of several power terms. This required that the exponential terms of Pellat's hypothesis should be infinite in number-which deprived the hypothesis of physical meaning. It would be more logical, therefore, to begin with the power terms as fundamental, and to discard the false start given by Pellat. Mr. ADDENBROOKE stated that in order to get at the proper theory of experiments the best dielectrics should not be used, as the effects were so minute that the chances of error were great. With poorer dielectrics, the actions were on a greater scale and easier to observe. Using an ellipsoid suspended at 45° to the electric field, he had been able to carry his experiments down to a frequency of one cycle in two hours, taking, of course, time readings of current and voltage. Dr. Ashton had not mentioned a paper by Wagner, which seemed to cover much the same ground. Prof. C. H. LEES mentioned a later paper on the subject by Curtis, who had found that Schweidler's equations held if several terms were taken. Dr. ASHTON, in reply, said that in Pellat's original paper there were results which showed that over a certain range the charging current could be represented by a constant times t-", and that more than one exponential term might be required. His own experiments showed that it = Bt-n held over two or three days. The difficulty was to keep the temperature constant over a long time. Another difficulty was that if circuit were broken for a fraction of a second, the results were vitiated. In reply to Dr. Russell, he believed it = Bt-n represented Fleming and Dyke's results better than i¡ '= a+bt. = CHEMICAL NEWS, Dec. 12, 1913 Ionisation by Collision. 293 A paper entitled "A Lecture Experiment to Illustrate | Solvay's offers, and further passed the following resolution: Ionisation by Collision and to show Thermo-luminescence" was read by Mr. F. J. HARLOW. A method of demonstrating to an audience both ionisation by collision and the reduction of the sparking potential by the presence of initial ionisation is described in the paper. A spherical bulb, in which an electrodeless discharge is excited, contains two coils of platinum wire, coated with lime and aluminium phosphate respectively, which can be heated by means of a current. Within the range of pressure for which the electrodeless discharge can be excited, provided the discharge is not too intense, both the lime and aluminium phosphate, on being raised to incandescence, give a considerably increased effect, showing that the ions given off by these substances are effective under the action of the induced E.M.F. in producing an enormous number of others by collision. The lower limit of the range of pressure over which the discharge can be excited with a given induced E.M.F. is considerably extended by heating either the lime or the aluminium phosphate, the former, however, being much more efficient than the latter in this respect. This extension of range is an illustration of the fact that the sparking potential is diminished by the presence of ions, and by negative ions more than by positive. If the lime and aluminium phosphate are subjected while cold to an intense discharge for some time they exhibit the phenomenon of thermo-luminescence, the lime on being warmed gently giving out a golden yellow luminosity and the aluminium phosphate a blue. The effect with lime apparently increases with an increase of electrical activity caused by continued heating, which suggests that the thermo-luminescence and electrical activity are closely associated. This suggestion receives support from the fact that lime alone does not exhibit thermo-luminescence, and that both lime on platinum and lime on nickel, which are electrically active, do. Further experiments are being made on this point, which the author thinks will throw light on the origin of the anomalous electrical activity of lime on platinum. A demonstration of these experiments was given. INTERNATIONAL ASSOCIATION OF CHEMICAL SOCIETIES. EXTRACT FROM THE MINUTES OF THE THIRD SESSION OF THE COUNCIL. AT the third session of the Council of the International Association of Chemical Societies, held at the Institut Solvay, Parc Léopold, Brussels, from September 19 to 23, 1913, Prof. Haller gave an account of the negotiations which had taken place between M. Ernest Solvay and certain representatives of the International Association, and which had resulted in the offer by M. Solvay of an unconditional gift of 250,000 francs to the Association. M. Solvay further proposed to found an "International Institute of Chemistry," having for its object the facilitation of the study and progress of chemistry, without, however, excluding problems belonging to other branches of the natural sciences, provided that these have some bearing on the science of chemistry. The Institute will be governed by an "Administrative Commission" of three Belgian members (one nominated by His Majesty the King of the Belgians, a second by the University of Brussels, and a third by M. Ernest Solvay), and by a Delegation of the Council of the International Association of Chemical Societies, consisting of Messrs. Haller, Ostwald, and Ramsay. Of the Institute's annual income of from 55,000 to 56,000 francs two-thirds will be placed at the disposal of the International Association of Chemical Societies, whilst the remaining one-third will be employed in establishing scholarships for Belgian students. The Council gratefully accepted M. | -"Ces sessions se tiendront autant que possible une fois sur deux à Bruxelles." M. Solvay has provided the International Association with offices in Brussels, where the archives will be kept, and a permanent secretary is to be appointed to take charge of them and to conduct the general business of the Association. Prof. Haller was elected President of the Association for the ensuing year, and it was decided that the next meetings should be held in Paris some time during the first fifteen days of September, 1914. Prof. Guye presented a report on the "Unification of Abbreviations of Titles for Scientific Journals used in Chemical Memoirs," and it was decided that, should the editors of all journals publishing chemical memoirs consider it advisable, the Council of the International Catalogue of Scientific Literature should be consulted, and a list of abbreviations should be circulated among the societies affiliated to the Association, with an invitation definitely to adopt the abbreviations for all future publications. Prof. Werner read and explained the Report of the Commission appointed to consider the question of "the mitigation of the difficulties arising from the existing multiplicity of languages employed in scientific literature," and after prolonged discussion the Committee was reappointed to report to the next meeting of the Council, more particularly on three points : (a) The publication of an International Journal of Abstracts in three languages. (b) The publication of three editions of an International Journal of Abstracts, namely, in English, French, and German. (c) The publication of an International Journal containing translations into either English, French, or German of original papers appearing in the lesser known languages. The Council received and adopted the report from the Commission for the Unification of Physico-Chemical Symbols. The following list gives some of the symbols recommended : for hydrogen and oxygen, which should always be placed | From these reactions precipitates of phosphides are at the end of the formula. The recommendations of the Austrian and Russian National Committees for indicating the relative number of atoms of each element in the molecule are approved; e.g., N2O5 becomes dinitrogen pentoxide instead of nitrogen pentoxide. In order to obtain shorter names for substances it is considered desirable to indicate the valency of the positive component by means of a suffix, the valencies one to eight being represented by the suffixes o, a, i, e, on, an, in, en in the order given; e.g., the two chlorides of mercury would be respectively named mercuro. and mercura-chloride. It is recommended that an International Commission, composed of one member from each country represented in the Association, be appointed with Prof. Werner as chairman. obtained of varying colour according to the metal contained in them; their general formula is P,M, analogous to that of lead phosphide, P,Pb, which has been analysed. All these compounds may be regarded as salts of the acid P,H2, which is Le Verrier's solid hydrogen phosphide. Hydrogenation of Secondary Alcohol derived from Furfurol.-Roger Douris.-The hydrogenation of ethylfurfurylcarbinol over reduced nickel gives a mobile liquid from which the following products can be separated by fractional distillation: (i.) Boiling-point 127-130°, under atmospheric pressure. The products are chiefly propyloxybutane and propyloxybutadiene. (i.) Boilingpoint 140-150°, under atmospheric pressure. This fraction contains dipropylketone. (iii.) Boiling-point 87-90°, under 15 mm. pressure. The principal product is ethyltetrahydrofurfurylcarbinol. (iv.) Boiling-point 110-120°, under 15 mm. pressure. This fraction is a CHEMICAL NOTICES FROM FOREIGN very syrupy liquid in which there is a glycol, C2H1602. SOURCES. NOTE. All degrees of temperature are Centigrade unless otherwise CH2= C(Dm)2 is obtained. If the liquid, which is left expressed. Comptes Rendus Hebdomadaires des Séances des l'Académie des Sciences. Vol. clvii., No. 17, October 27, 1913. Refraction and Magnetic Rotation of Compounds with Acetylenic Function.-Ch. Moureu, P. Th. Muller, and J. Varin.-The proximity of the triple bond and of a negative (or slightly saturated radical) gives rise in the fatty series to a more or less marked exaltation of the refraction, which is greatly increased in the aromatic series by the proximity of the triple bond and the phenyl group. The rotation is qualitatively affected in the same way as the refraction (except in the case of acetylenic diacetal, which exhibits a depression). But if a table showing the relative exaltations is consulted, it is seen that the magnetic rotation is more sensitive than the refraction to the reciprocal influence of the slightly saturated radicals and the acetylenic bond. This sensitiveness is specially noticeable in the aromatic series. Action of Magnesium Methyl and Ethyl Iodides on Michler's Ketone.-P. Lemoult.-When magnesium methyl iodide acts on Michler's ketone the hydrocarbon after all this hydrocarbon is deposited is examined, it is found to contain three compounds :-(i.) The dimer of CH2=C(Dm)2. (ii.) A compound containing 83 per cent C, 8 per cent H, 9 per cent N. (iii.) A compound containing 82 per cent C, 8 per cent H, 10 per cent N. With the ethyl compound the only product is the hydrocarbon CH3-CH=C(Dm)2. MISCELLANEOUS. Simple Process to Detect Nitrous Acid in presence of Nitric Acid.-A. Leclère.-An equal volume of a syrupy solution of citric acid is added to the solution to be analysed. Thus a dense liquid is obtained, and by means of a drawn-out pipette a 3 or 4 per cent solution of ammoniacal ferrous sulphate can be superposed on it. In presence of nitrous acid a brown ring appears at the surface of separation of the two liquids, while even a concentrated solution of a nitrate gives no reaction, since citric acid does not expel nitric acid from its salts. In presence of sulphides it is best to treat the solution with zinc acetate and filter off the zinc sulphide formed. Preparation of Aluminium Ethylate. -Clément Berger.-Aluminium ethylate can be prepared by the action of aluminium amalgam on absolute alcohol containing a little sodium ethylate. A small amount of sodium is dissolved in alcohol, and sheets of aluminium, amalgamated by immersion in a saturated solution of mercuric chloride, are introduced into the solution. Bubbles of hydrogen are produced, and a grey precipitate of aluminium ethylate containing a little alumina is deposited. 3C2H6O+Al = (C2H5O)3Al+3H. Aluminium ethylate is very readily decomposed by water, and hence all traces of MONDAY, 15th.-Royal Society of Arts, 8. (Cantor Lecture). moisture must be avoided. It is decomposed by heat. MEETINGS FOR THE WEEK. "The Measurement of Stresses in Materials and Structures," by Prof. E. G. Coker, D.Sc. TUESDAY, 16th.-Physical, at 3 and 7. Exhibition of Physical Apparatus. "Soap Films, by L. Brennan. Production of Vibrations on Loaded and Unloaded Strings," by J. A. Fleming. WEDNESDAY, Presence of Gallium in Commercial Aluminium and its Separation.-Ch. Boulanger and J. Bardet.Gallium appears to be very widely distributed in nature, and the spectrographic examination of many specimens of commercial aluminium always revealed its presence very distinctly. To separate it the aluminium was dissolved in HCl, and the metal always present, such as Cu, As, Sb, Sn, THURSDAY, Pb, Zn, Fe, Na, is separated by appropriate treatment; i.e., by sulphuretted hydrogen in either hydrochloric or acetic solution. After this treatment had been repeated three times only the gallium and a small amount of iron remained. Finally, treatment with boiling potash completely eliminated the iron. Metallic Phosphides derived from P5H2.-R. Bossuet and L. Hackspill. By the action of liquid ammonia the alkaline phosphides, P5M2, are converted into crystalline ammoniacal phosphides, which are soluble in liquid ammonia. In this state they undergo double decompositions with metallic salts dissolved in the same solvent. 17th.-Royal Society of Arts, 8. "The Channel Tunnel," by Arthur Fell, M.P. Microscopical, 8. "The Binocular Microscopes of the Past, and a New Form of the Instru ment," by C. Bock. 18th-Chemical, 8.30. "Chemical Examination of Sarsaparilla Root," by F. B. Power and A. H. Salway. "Aromatic Compounds obtained from the Hydroaromatic Series - Part III., Bromoxylenols from Dimethyldihydroresorcin," by A. W. Crossley and N. Renouf. "Equilibrium of Dilute Hydrochloric Acid and Gelatin," by H R. Procter. "Metallic Derivatives of Acetylacetone and Acetyl-mesityl Oxide," by G. T. Morgan and H. W. Moss. "Constitution of the Ortho-diazoimines Part IV., Isomeric Benzenesulphonyl-3: 4-tolylenediazoimides" by G. T. Morgan and G. E. Scharff. "Organic Derivatives of Silicon-Part XXI., The Condensation Products of Diphenylsilicanediol," by R. Robison and F. S. Kipping. "Sorption of Gases by Celluloid," by V. Lefebure. Catalogue and Sample free. Quotations given for Apparatus to Special Design. KINDLY MENTION "CHEMICAL NEWS." NOW READY. The SILICA SYNDICATE, Ltd., 82, Hatton Garden, London, E.C. GENERAL INDEX TO THE CHEMICAL NEWS, Vols. 1 to 100 (1860 to 1909). Pp. 712. Price £2. (Carriage extra, weight 3 lbs. 9 ozs). PRESS OPINIONS. "It is, without doubt, the finest example of a General Index which has been published in connection with chemistry." -Chemist and Druggist, May 3, 1913. "It is an excellent compilation, and sore to be of great service to chemical readers generally."-Pharmaceutical Journal, May 10, 1913 "The Chemical News is to be congratulated on having had the courage to undertake and the perseverance to carry out a work of this description. The task has been carried out in a thoroughly workmanlike spirit, and as it contains a key to the history of every development in chemistry during the fifty years covered it should prove extremely useful to everyone interested in science "- Journal of the Royal Society of Arts, May 23, 1913. "In indexing articles, the spelling and nomenclature originally adopted by the authors has been adhered to. . . . So far as has been noticed, this is the one blot on an excellently planned and finely executed work of a monumental character."-Journal of the Society of Dyers and Colourists, June, 1913. The Index under review is one that will be necessary to every reader of the Chemical News, and, indeed, will be useful to all chemists, giving, as it does, references to so many subjects, such as university intelligence, &c., which are found in perhaps no other chemical journal."-Nature, June 19, 1913. "A great service has been now performed for the active chemist in making this mass of material easily accessible through a general index. 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